No abs or esp or ebd

[Athey]

The dash lit up this morning along with the message run flat indicator inoperative. The breakdown guy came up with the following;
12 fault codes with brakes
Both front rpm sensors,
No can message received from Ecu intermittent,
Steering angle sensor intermittent,
ESP control unit internal fault intermittent.
I have had a read round and have ordered 2 new front sensors, but breakdown guy seems to think the ecm is buggered. Any ideas?

 

[AMGeed]

Have you checked the battery voltage with the engine off? You should have a minimum of 12.3V.
Low voltage seems to cause various spurious faults with Mercedes.

Just an avenue to check and rule out. Both wheel speed sensors and a steering angle sensor going bad at the same time seems very odd.

 

[Athey]

Breakdown guy checked that as well. All I can think of is put the sensors on and take it to my local indy to check with star and clear the codes. Had no problem whatsoever till today.
The only other thing I can think of is it rained hard yesterday, but no sign of water round the calliper where the sensor is screwed in.

 

[Smart320]

I would guess it is battery! Same on my ML
I had the message Run Flat Inoperative on my SLK , turned out it was the software on the exhaust valves needed updating. Would guess the breakdown guy not an expert on Mercedes

 

[Athey]

Will go back out in a min and check voltage, battery health showed good when mb serviced it a few weeks ago. Just worried it might ruin my holiday as doing the north coast 500 in 4 weeks, and all the camping gear, etc hammered what spare cash I have at the moment

 

[Athey]

Just checked battery 15.5v

 

[Athey]

Just checked battery 15.5v so no problem there

 

[AMGeed]

Just checked battery 15.5v so no problem there

I'm not so sure. It shouldn't be reading that high!

From Google
"In order to push energy into the battery, a higher voltage of about 14 volts is created. ... Higher than 15 volts indicates a fault in the charging system's voltageregulator or related circuits. If it's substantially excessive, this can cause electrical system and/or battery damage"

 

[Athey]

Oh dear. Sounds expensive. Any ideas on where to start?

 

[AMGeed]

Sounds like its overcharging and really needs some proper diagnostics with Star done.
You did test it with the engine off didn't you? I'd expect 14V - 14.5V with the engine running, but no more.

They will probably test the voltage regulator on the back of the alternator to see if its overcharging.

 

[Athey]

Yes I tested it with everything off. Hopefully it might be the voltage regulator which I’ve just had a quick read on.

 

[AMGeed]

Fingers crossed for you mate. At least a voltage regulator is a cheap(ish) fix.

 

[Athey]

I’ll keep you updated. Many thanks about the battery, I wouldn’t have thought about that at all. Just hope the high voltage hasn’t fried anything.

 

[AMGeed]

 

[Neiltodd]

I would go with the battery too.

 

[oldguy57]

Had the same problem with the SL and it was the voltage regulator at fault. Not hugely expensive to sort.

 

[Athey]

Hi all, went to take the car for diagnostics today, and as usual, the dash lit up at 15mph. Stopped at the cash machine to get some money, and lo and behold, nothing lit up as I drove off.
Diagnostics showed no signal to the ecm and cleared all the fault codes. Reran the diagnostic again and everything ok. I mentioned the battery’s voltage and he checked that, just showed low voltage. Got a new battery from Mb and also picked up 2 front abs sensors. Looks like it was the battery after all.
If anyone else has the same problem, I’d advise get it on star to check it out before anything. It soon pinpointed the problem, and huge thanks to the mech at Thornleys garage at Walton le dale. Good with mercs.